Bacterial Infections involving multi-drug resistant (MDR) phenotypes constitute a worldwide health concern. Anonidium mannii is used in Cameroon folk medicine for the treatment of various diseases (yellow fever, malaria, measles, typhoid fever, gastroenteritis, burns, inflammation and pain). The present work was designed to assess the antibacterial properties of the ethanol extract of the stem bark of Anonidium mannii and the effects of its association with antibiotics on MDR Gram-negative bacteria over-expressing active efflux pumps. The antibacterial activities and the ability to potentiate antibiotic effects of the ethanol extract were evaluated in vitro against eighteen Gram-negative bacteria expressing MDR phenotypes, using broth microdilution method. The preliminary phytochemical analysis was performed through standard methods. Acute and sub-acute toxicity was investigated by oral route in Wistar rats. Ethanol extract displayed moderate to low antibacterial activity on at least 21.8 % of the tested bacteria, with MIC values ranged from 128 to 1024 μg/mL and showed synergistic effects with many antibiotics against MDR bacteria. No adverse effects or mortality were observed throughout the duration of the acute toxicity experiment (LD50 ˃ 2000 mg/kg). In daily oral administration for 28 days, the ethanol extract is relatively non-toxic. The overall results of the present study provide information for the possible use of Anonidium mannii in the control of Gram-negative bacterial infections including MDR species as antibacterials as well as resistance modulators.

BIOGRAPHY

Aristide Mokale received a BSc degree and Postgraduate Diploma in Biochemistry at the University of Abomey-calavi. He obtained in 2009 an MSc in Clinical biochemistry and Pharmacology at the University of Dschang (Cameroon) before pursuing a PhD in Biochemistry of natural products from the University of Douala (Cameroon). Mokale spent several months at the Francois-Rabelais University of Tours (France), VNS Group of institutions (India) and CSIR-Indian Institute of Chemical Biology (India) as a postgraduate fellow. Since 2013, Mokale is employed on full time basis as a Lab Technician and Administrative staff at the Institute of Medical Research and Medicinal Plants studies (Cameroon). Mokale' research interests cover screening of plants bioactive compounds and plant extracts for their pharmacological activities. Mokale has published nine peer-reviewed research articles, as well as one book chapter.